Wood grinder



Nov. 13, 1928. 1

1,691,101 --x. WINKLER I woon GRINDER Filed Sept. 1927 2 Sheets-Sheet i t I I e v l i L Q NW. 13, 1928. 1,691,101 X. WINKLER WOOD GRINDER Filed Sept. 1927 Z-Sheets-Sheet 2 Patented Nov. 13, 1928.

UNITED STATES P 1,691,101 FFICE.

ATENT. O

WINKLEB, OI WEISENBACHFABRIK, GERMANY, ASSIGN OR TO THE FIRM:

' I. HOLTZHANN & OIE. .A.-GES., OF WEISENBACHFABRIK, GERMANY.

WOOD GRINDER.

Application. filed September 8, 1927, Serial No. 217,874, and in Germany September 6, 1920.

This invention refers broadly to re ulating-means in connection with means of preparing mechanical wood pulp by the forcing of blocks of wood against a revolving grindstone, and it is intended to devise means of overcoming the drawbacks resulting from irregularities of pressure of the wood against the grindstone, and to insure a practically uniform grinding operation. With these and other objects in view the invention comprises electrically operated regulating means, adapted to affect and control both the operation of the means for the feeding of the wood and for the holding thereof against the grinder, aswell as theoperating means for the grinder itself. Devices of the kind herein referred to adapted to produce a continuous, uninterrupted and substantially uniform grinding action generally comprise a grindstone with a superimposed tubular vertical shaft for the reception and the feeding of the wood to the grinder and means in connection therewith to press the wood with a certain pressure against the grindstone, means being provided to regulate the pressure of the wood within substantially wide limits in accordance with the varying condition of the wood, the character of the pulp roduced and the amount and rate of drivlng power at disposal for the operation of the motor engine or the like. In. accordance therewith the feeding, propelling and press ing means for the wood which are generally provided at the sides of the feeding conduit, such as chains, worm wheels, cellular feeding wheels and the like are operated by regulatable means which are de endent in their operation on the efiiciency o the main driving means for the grindstone, s'gthat by varyin the rate of propulsion of thewood and the frictional pressure of the wood the output and efliciency of the operating means will.

be kept constant. Now my invention broadly considered resides in'the fact that the adjustment of the regulating means of the woodfeeding devices is effected by means of an electric relay or the likewhich is controlled by the current of the main engine operating the grindstone, the regulating means comprising a liquid operated switch, a' mercury switch for instance, which so arranged and constructed that it is under the influence of the induction relay operated by the circuit of the main engine and depending upon theload in such circuit. The regulating device is preferably adapted to provide a Wide range of regulation with but a comparatively small displacement of the relay. As compared with the'prior art the invention among other important objects is advantageously distinguished by the fact that the change of revolutions of the feeding motor engine for the wood in view of its direct dependence upon the load-in the main operating engine takes place very rapidly. Any undesirable excessive or too rapid regulation may easily be avoided by the combination with damping means, a damping pump for instance. Then there is the advantage that the consumption of power of the electric motor employed for the feeding of the wood is relatively low, amounting to only a fraction of the power required for the oil-motor-engines heretofore usually employed.

The invention is shown on the accompany-v ing drawings in several forms of embodiment way'of exemplification in diagrammatic representation in Figures 1 to 4.

In the drawings 1 is a suitable motor engine, for instance an electric alternating current three-phase motor which is operatively connected tothe grindstone 2. Above the grindstone is a tubular shaft or conduit 3 for the reception and the feeding of the logs turn is electrically connected to the rotatin or reversing magnet 9 which is provide with a fixed resistance 10, and is in operative connection with a weight 11,suitably connected to the shaft of the magnet 9. The weight is. arranged to oppose the rotation of the magnet in a certain direction. To the weight a regulating resistance or the brush-bridge 16 (Figure 2) may be connected in accordance with the use'of either an asychronous motor or a polyphase-coIlector-motor (Fig. 2) 18 being employed for the feeding and propulsion of the wood.

Upon starting the main driving motorengine 1 only the idle not operatmg current will flow in the stepped transformer 7, 8. The weight 13 overcomes the pulling force of the rotatable magnet 9, the regulating resistance ofthe feeding-motor 5 is short-circuited, or in the case of the polyphase-motor Figure 2 there is a corresponding adjustment of the brushes for the maximum number of revolutions. The feeding motor 5 will therefore be rotated at its highest speed and will impart a corresponding high velocity to the woodfeeding means 4. The logs of wood are thereby forced with increasing force against the grindstone, and the main driving-motor 1 is under an increasing load, sothat the induced current in the stepped transformer is increased, and a pulling force corresponding thereto is imparted to the rotary magnet 9. In consequence thereof the weight 11 is raised and the regulating resistance 16 which is included in the circuit 6 of the feedingand propellin motor 5 or the brush-bridge 16 in the case 0 the polyphase motor of Fig. 2 is correspondingly displaced and re-adjusted. The

Y regulating resistance 16 is connected to a series of contacts 14 which in the embodiment of Figure 1 are arranged at difierent levels within the relatively narrow tubes 15 of the mercury tank 12 of a mercury switching device constituted by a system of communicab ing tubes and comprising a broad tube 19 and a plurality of relatively narrow tubes 15, three for instance. A plunger 13 which works in the broad tube 19 is connected to the weight ,11, so that by the reciprocation of the weight 11 the mercury in the leg 19 and in the tank 12 will be correspondingly depressed and respectively raised in the narrow legs 15 where it will reach the different contacts connected respectively to the regulating resistance 16, and it is obvious that by this means the opera tion of the feeding and ropelling motor 5 can be readil regulated and controlled in accordance wit the working load on the prime or main motor 1. Thus, inasmuch as the 'pullin force of the rotating magnet 9 depends directly on the efliciency ofthe said prime motor and 1s adapted to act directly u on the regulating resistance or to adjust t e brushes in accordance with the embodiment of Fig. 2, a very rapid adjustment of the required-speed of feeding movement is obtained, and on the other hand the fluctuations of the efliciency and of the working load of the .prime motor 1 are thereby overcome and eliminated, the motor assuming its regular rate of movement. Then, there is the additional advantage that only relatively low operating forces are required for the rotary relay magnet 9 and notwithstanding the comparatively short paths of movement of the relay and of the plunger 13 a very delicate adjustment and great sensibility of the regulating device is obtained.

When employing asynchronous motors as feeding and propelling devices the movability of the mercury with proper adjustment allows of an acceleration of the start by suitable overre lation, so as to further increase the sensi bihty of the regulator.

In the exemplification of Figure 2 a polyphase-collector-motor is employed as a feedmg means for the logs of wood. In this fi' ure 18 is the motor, 17 are the brushes and 6 the brush-bridges. By suitable connection with the weight 11, diagrammatically indicated in this figure the respective relative position of the parts 16 and 17 may be adusted.

In case direct current is at disposal aside from the use of alternating current for the prime or main motor 1, the feeding and propelling motor 5 may also be in the form of a direct current motor. The field of this feeding motor which should be built as a shuntdirect current motor is produced by the direct current voltage 'and the regulation of the number of revolutions is effected by the variat-ion of a regulating resistance included in the armature circuit in the same manner, as set forth with reference to a polyphas'e-asynchronous motor.

-In the exemplification shown by' the diagram according to Figures 3 and 4 the relay comprises substantially a solenoid 20 which is included in the secondary circuit of a trans former or the like 21. By means of a shunt resistance 30 with regulatably disposed controlling contacts the strength of the current I in the solenoid 20 or in an equivalent electromagnetic operating device and the lifting and pulling force thereof may be adjusted to different values. The core of the solenoid may be connected to a plunger 13, as shown in the exemplification above described, or the core may be connected to an ordinary controlling valve to regulate the flow of an operating fluid or liquid. The controlling valve in the embodiment shown in Figure 3 is preferably constructed as a balanced valve which works in the controlling cylinder. 31. In the emob'diment shown this cylinder is provided with four ports or connecting conduits for the admission and discharge of the pressure fluid or liquid. 28 is the mercury container which is provided with the communicating narrower and somewhat higher leg 32 in which the regulating resistances29 are disposed which are included in the circuit of the feeding and log-propelling motor 5. The

conduit 25 is assumed to connect the upper 1 part of the wider leg of the mercury switch with the cylinder 31, and is continued by the oppositely arranged discharge condult 24.

The conduit 26 at the bottom part of the controlling cylinder 31 may be employed'for instance as feeding conduit .fpr the pressure fiuidand is continued by the communicating conduit27 which leads into the mercury container 28, terminating above the level of the mercury in the position of rest. In this position the mercury in the narrower leg 32 is The number of rotations and the torque of this motor are, of course, variable within wide limits. If, on account of insuflicie'ntcontact of the wood against the grindstone the current of the mainor prime motor 1 is decreased below the predetermined value, the'steering and controlling valve 22 on account of the correspondingly reduced strength of the field of the solenoid or the like descends, as shown at A in Figure 3 of the drawing, so as to open communication for the pressure fluid or liquid with the interior of the container 28.- Thus the pressure fluid will depress the level of the mercury in the broader leg and raises'it in the narrower leg containing the resistances 29, and in accordance with the degree of pressure produced a correspondingly larger or smaller amount of the resistance 29 will dip into the mercury, so that in consequence of this short-circuiting action the feeding motor 5 will increase its number of revolutions and will force the wood with greater force against the grindstone, until the load on the main motor 1 has reached the desired value.

If, on the othenhand, the load on the main motor 1 on account of excessive frictional contact of the wood against the grindstone becomes too high, the field strength of the sole noid or the like will be correspondingly increased, so that the controlling valve 22, 23 will be raised into the position B of Figure 4. This causes the throttling or interruption of the admission of pressure fluid or liquid, while the return and discharge conduits 25, 25 are opened. As a result thereof the mer cury in the broader leg 28 ascends and the mercury in the narrower leg 32 descends and the short-circuit of the regulatingres'istance is broken, and in view of the resulting increase of rotor-resistance the feeding or propelling motor 5 will now run with decreased speed or will be stopped, until thedesired value of the current strength for the main motor has been obtained. Thus, the controlling and regulating valve 22, 23 will oscillate, so as to respectively open and close one of the communicating passages, and thereby regulates the rate of rotation of the feeding motor and insures the desired load on'the prime motor.

The resistances 29 should be made of highgrade material and are preferably cooled by any suitable means. Cooling by air may be used as the simplest means of cooling, or water-cooling may be resorted to in which casethe slight conductivity of the water does not substantially interferewith the operation 7 of the resistances 29.

With this kind of relay and manner of regulation a practically unlimited adaptability of the device istpro uce as compared with the ble feeding means operated by oil-fed working engines and the like.

It should of course be understood that the invention is not limited to the particular exemplifications herein shown merely. by way of-illustrating the principles of the invention which is susceptible of modifications and changes in accordance 'with'varying conditions of application, and the convenience of the user and within the scope and spirit of the invention, as defined in the appended claims.

I 'claim:

1. In a wood-grinder the combination with a rotating grindstone, driving means for the stone and electrically operated wood-feeding means cooperating therewith, of a liquidoperated switch, adapted for operative connection with the wood-feeding means, an electric relay, opcratively associated with the stone-driving means, and actuating means for the switch connected to the relay.

2. In a wood-grinder the combination with a rotating grindstone, driving means for the relay and influencing the liquid of the switchregulator and connection between said regulator and the wood-feeding means.

3. In a wood-grinder the combination with a rotating grindstone, driving means for the stone, and electrically operated wood-feeding means cooperating therewith, of a liquidoperated stepped electric switch-regulator, an electric relay intermediate the regulator and the stone-driving means, and adapted to be operated ,thereby, a liquid-container on said relay, and pressure producing means in said container and connected to the relay, and

connection between saidregulator and the wood-feeding means.

4. In a wood-grinder the combination with a rotating grindstone, driving means for the stone, and electrically operated wood-feeding means cooperating therewith, of a substantially U-shaped liquid container, comprising unequally dimensionedlegs, a supply of liquid in said container and electric regulating and switching means on said container adapted to be bridged by the movement of the liquid, connections of said regulating and switching means with the Woodieeding 7. In a woodrinder the combination with means, means in said container, producing arotating grin stone, electric driving means 4 liquid-pressure, an electric relay connected to the pressure-producing means and adapted to be operated by variations of efficiency of the stone-driving means.

5. In a wood-grinder the combination with a rotating grindstone, driving means for the stone, and electrically operating woodfeeding means cooperating therewith, of a substantially U-shaped liquid container, comprising unequally dimensioned legs, a supply of'mercury in said container, and electric regulating and switching means on said container normally above the level of the mercury and adapted for differently large electric engagement with the mercury, and connected to the wood feeding means, pressureproducing means in said container above the mercury, and an electric relay operatively connected to the pressure-producing means and adapted for operation by variations of.

the eificiency of the stone-driving means.

6. In a wood-grinder the combination with a rotating grindstone, driving means for the stone, and electrically operated wood-feeding means-cooperating therewith, of a liquidcontainer, a supply of mercury in said container, and electric regulating and switching means on said container above the normal level of the mercury and adapted for differently large electric engagement with the mercury and connected to the wood-feeding means, means to raise the level /0f the mer-- cury, an electric relay, connected to the levelraising means electrically influenced by the stone-driving means and operable by the variations of efliciency thereof.

for the stone, and electrically operated woodfeeding means cooperating therewith, of a differently movable electric relay, inductioncurrent-influenced operating. means for said relay, connected to the stone-driving means,

a substantially U-shapedcontainer comprising differently dimensioned legs, current regulating means in one of said legs connected to the wood-feeding means, a supply of mercury in said container, a pressure-fluid conduit communicating with the other leg of the container, and a plunger movable in said conduit and operatively connected to the electric relay, and adapted to produce different pressures on the mercury and changeable engagelnent thereof with the current regulating means.

8. In a wood-grinder the combination with a rotating grindstone, electric driving means for the stone and electrically operated woodfeeding means cooperatin therewith, a. stepped rotary magnetic switch, controlling means for said switch, operatively connected to the stone-driving means, a liquid-container, a supply of mercury in said container, means operatively connected to the ma netic switch and operatively amociat'ed with the mercury and adapted to change the level thereof, and current regulating and proportioning means onthe container and connected to the wood-feeding means and adapted for difierently extensive engagement with the mercury of the container.

In testimony whereof I have aflixed my signature.

XAVER WINIUJER. 

